Toner cartridge and image forming apparatus

Abstract

A toner cartridge includes a cylindrical casing configured so as to be rotatable, a discharge port discharging toner inside the casing to a storage section of a developing unit, and a plurality of slanted ribs on an inner circumferential surface of the casing with one or more discontinuous sections formed in between. The plurality of slanted ribs each include a first slanted rib located on a downstream side of the discontinuous section and a second slanted rib located on an upstream side of the discontinuous section with respect to a toner flow direction. A first end portion formed on the discontinuous section of the first slanted rib is disposed at a position relatively shifted by a predetermined length toward a toner inputting side in relation to a position on an extension line of a second end portion formed on the discontinuous section of the second slanted rib.

What is claimed is: 
     
         1 . A toner cartridge that is removably attached to a developing unit and replenishes toner to the developing unit, the toner cartridge comprising:
 a cylindrical casing that is rotatable and is provided with a discharge port that discharges the toner into the developing unit;   a plurality of slanted ribs provided on an inner circumferential surface of the cylindrical casing to transport the toner to the discharge port by a rotation of the cylindrical casing, each of the plurality of slanted ribs including a first slanted rib and a second slanted rib that are both arranged in a toner flow direction around a rotational axis of the cylindrical casing; and   a discontinuous section linearly extending from a first end to a second end of the cylindrical casing along the rotational axis of the cylindrical casing, the discontinuous section passing through a space between the first slanted rib and the second slanted rib, wherein:   in each of the plurality of slanted ribs the first slanted rib is located on a downstream side of the discontinuous section with respect to the toner flow direction;   in each of the plurality of slanted ribs the second slanted rib is located on an upstream side of the discontinuous section with respect to the toner flow direction;   a plurality of first slanted ribs each has a first end face facing the discontinuous section, and a plurality of first end faces are arranged to be substantially flush with each other; and   a plurality of second slanted ribs each has a second end face facing the discontinuous section, and a plurality of second end faces are arranged to be substantially flush with each other.   
     
     
         2 . The toner cartridge according to  claim 1 , wherein each of the plurality of first end faces is disposed at a position relatively shifted toward the first end or the second end of the cylindrical casing in relation to a position of the corresponding second end face. 
     
     
         3 . The toner cartridge according to  claim 1 , wherein each of the plurality of first end faces is disposed at a position shifted toward the first end or the second end of the cylindrical casing in relation to a position on an extension line of the corresponding second slanted rib. 
     
     
         4 . The toner cartridge according to  claim 1 , wherein each of the plurality of first end faces is disposed at a position relatively shifted toward the first end or the second end of the cylindrical casing in terms of a projection that is perpendicular to the rotational axis of the casing. 
     
     
         5 . The toner cartridge according to  claim 1 , the cylindrical casing comprising:
 a positioning portion that is provided with the discharge port, and positions the discharge port to a predetermined position around the rotational axis of the cylindrical casing; and   a rotating portion that is configured to rotate the cylindrical casing about the rotational axis of the cylindrical casing in relation to the positioning portion,   wherein the rotating portion is provided with the plurality of slanted ribs.   
     
     
         6 . An image forming apparatus comprising:
 a toner cartridge;   a photoreceptor on which an electrostatic latent image is formed; and   a developing unit configured so that the toner cartridge is removably attached thereto, the developing unit forming a toner image by supplying the photoreceptor with toner replenished by the toner cartridge, wherein:   the toner cartridge includes:
 a cylindrical casing that is rotatable and is provided with a discharge port that discharges the toner into the developing unit; 
 a plurality of slanted ribs provided on an inner circumferential surface of the cylindrical casing to transport the toner to the discharge port by a rotation of the cylindrical casing, each of the plurality of slanted ribs including a first slanted rib and a second slanted rib that are both arranged in a toner flow direction around a rotational axis of the cylindrical casing; and 
 a discontinuous section linearly extending from a first end to a second end of the cylindrical casing along the rotational axis of the cylindrical casing, the discontinuous section passing through a space between the first slanted rib and the second slanted rib; 
   in each of the plurality of slanted ribs the first slanted rib is located on a downstream side of the discontinuous section with respect to the toner flow direction;   in each of the plurality of slanted ribs the second slanted rib is located on an upstream side of the discontinuous section with respect to the toner flow direction;   a plurality of first slanted ribs each has a first end face facing the discontinuous section, and a plurality of first end faces are arranged to be substantially flush with each other; and   a plurality of second slanted ribs each has a second end face facing the discontinuous section, and a plurality of second end faces are arranged to be substantially flush with each other.